1. Field of the Invention
The present invention relates generally to the mounting and support of hard disk drives for computers, and more particularly relates to apparatus for removably supporting a plurality of hot plug-connected hard disk drives.
2. Description of Related Art
Hard disk drives for a file server or other computer are often mounted, in a vertically spaced array external to the file server, in a rectangular sheet metal "cage" structure within an external disk drive support housing. For operational convenience and flexibility, each disk drive is typically "hot plug" connected within the support housing. This type of electrical connection permits any of the supported disk drives to be removed and re-installed within the support housing without disturbing the operation of the other disk drives.
Under a conventional practice, each disk drive is mounted atop a printed circuit board having a rear card edge portion which is insertable into a back plane hot plug socket within the cage structure. To install each disk drive within the cage, side edge portions of its supporting printed circuit board are inserted into a pair of track members mounted on opposed side wall portions of the cage and then slid rearwardly along the tracks until the rear card edge portion of the circuit board is operatively received its associated hot plug socket at the back of the cage.
Some or all of the following problems, limitations and disadvantages are commonly associated with conventional hot plug disk drive support apparatus of this general type:
1. The use of a printed circuit board to underlie and carry each hard disk drive tends to increase both the complexity and cost associated with removably supporting each disk drive, and additionally presents sharp solder and wire points along the underside of the board which the installer must carefully handle to avoid scratches and nicks in his fingers when installing and removing the disk drive from the cage.
2. On some circuit board-supported disk drives, a considerable amount of manual pulling force is required to disconnect the board from its associated hot plug socket within the cage. On other conventionally supported disk drives, the circuit board is provided with pivotable ejection latches that must be screwed or pinned to the circuit board, thereby increasing the overall complexity and fabricational cost of the support system.
3. A typical method of securing an installed disk drive within the cage is to install a screw in the cage which acts as a stop to prevent removal of the disk drive assembly from the cage. This undesirably complicates and lengthens the individual disk drive installation and removal procedure.
4. Among other grounding-related problems, the necessary grounding between each disk drive and the sheet metal cage in which it is removably supported often requires fairly complex interconnections therebetween which tend to be rather tedious and time consuming to properly utilize. Additionally, the card edge hot plug socket interface area is normally exposed within the cage where it can be inadvertently touched by an installer trying to make alignment or other adjustments within the cage.
5. It is conventional to provide each disk drive with a plurality of indicating lights showing the operative state of the drive. However, under conventional practice, these indicating light arrays typically must be located on the support housing remote from the disk drives. This can lead to visual confusion as to which indicating lights are associated with which disk drive.
It can be seen from the foregoing that it would be desirable to provide external hot plug disk drive support apparatus, of the general type described above, with a variety of operational, fabricational and safety improvements. It is accordingly an object of the present invention to provide hot plug-connected external disk drive support apparatus incorporating such improvements.